The subject matter disclosed herein relates to systems for high-reliability bypass for multi-mode uninterruptible power supply (UPS) systems (e.g. double-conversion, ECO mode, etc.).
UPS systems are employed in a variety of applications to provide a constant source of voltage for a load. Some UPS systems include an inverter feed path that is connected in parallel with a bypass feed path. In a normal mode of operation, the UPS system may feed power to the load via the inverter feed path, which converts power from a power source into direct current (DC) power using a rectifier. The rectifier then provides the DC power to an inverter, which converts the DC power into a controllable alternating current (AC) power. The UPS system may then provide the controllable AC power to the load. Generally, the bypass feed path provides power to the load via a utility power source. As such, the bypass feed path provides the UPS system with another means for providing power to the load when the inverter feed path fails or is isolated for maintenance. In some situations, multiple UPS systems may be coupled in parallel to provide redundancy and/or extra power to the load. Conventional parallel implementations feature either a distributed bypass (i.e., every UPS system features its own bypass path) or a centralized bypass (i.e., single, separate bypass path while the various UPS systems only embed the rectifier-inverter path). Each approach has its drawbacks. The main disadvantages of distributed bypass are complexity, cost and footprint, while the centralized bypass offers limited reliability but lacks redundancy. Accordingly, improved systems and methods for bypass feed paths in parallel UPS installations are desirable.